The Definition of Art (Stanford Encyclopedia of Philosophy)
The definition of art is controversial in contemporary philosophy
A third sort of argument, more historically inflected than the first,takes off from an influential study by the historian of philosophyPaul Kristeller, in which he argued that the modern system of the fivemajor arts [painting, sculpture, architecture, poetry, and music]which underlies all modern aesthetics … is of comparativelyrecent origin and did not assume definite shape before the eighteenthcentury, although it had many ingredients which go back to classical,mediaeval, and Renaissance thought. Since that list of five arts issomewhat arbitrary, and since even those five do not share a singlecommon nature, but rather are united, at best, only by severaloverlapping features, and since the number of art forms has increasedsince the eighteenth century, Kristeller’s work may be taken tosuggest that our concept of art differs from that of the eighteenthcentury. As a matter of historical fact, there simply is no stabledefiniendum for a definition of art to capture.
Whether art can be defined has also been a matter of controversy
A fourth sort of argument suggests that a definition of art statingindividually necessary and jointly sufficient conditions for a thing tobe an artwork, is likely to be discoverable only if cognitive sciencemakes it plausible to think that humans categorize things in terms ofnecessary and sufficient conditions. But, the argument continues,cognitive science actually supports the view that the structure ofconcepts mirrors the way humans categorize things—which is withrespect to their similarity to prototypes (or exemplars), and not interms of necessary and sufficient conditions. So the quest for adefinition of art that states individually necessary and jointlysufficient conditions is misguided and not likely to succeed (Dean2003). Against this it has been urged that psychological theoriesof concepts like the prototype theory and its relatives can provide atbest an account of how people in fact classify things, but notan account of correct classifications of extra-psychologicalphenomena, and that, even if relevant, prototype theory and otherpsychological theories of concepts are at present too controversial todraw substantive philosophical morals from (Rey 1983; Adajian 2005).